Once upon a time, within the memory of those still living, if a film was successful, it inspired toys. Now, apparently, it's the other way around.

Transformers, from Armageddon director Michael Bay, is based not on a novel or a play or a screenwriter's inspiration, but on a line of Hasbro toys that have been hot tickets for more than 20 years. If you revere those toys, you already know that. If you don't, there isn't enormous reason to care.

Transformers, as any small boy can tell you, are robots from outer space with the ability to change shape to cars and other machines. Having fought each other for eons on their home planet, the good-guy Autobots and evil Decepticons transfer their battle to planet Earth, the improbable new home to an enormous object that is the source of all Transformer life.

Paradoxically, the problem with the movie is not with these Transformers. Computer technology has insured that watching these enormous toys come to life is everything fans could hope for. If this film were a lot shorter than its inflated 2 hours and 23 minutes, and if it kept its focus on the toys, it would be hard to argue with.

Humans, however, inevitably enter the story. The Transformers turn out to be looking for an 11th-grader played by Shia LaBoeuf, who spends his time dreaming about a potential girlfriend (as well as his first car), and that means that much of Transformers is spent with teenagers — who, as the key audience demographic, are fated to save the world.

The actors who play them look as much like 11th graders as I do, but the film has bigger problems, like keeping everyone awake while the toys are off the screen. Any film whose most resonant line of dialogue is spoken by a robot who says, "It's you and me, Megatron" has no business being 2 hours and 23 minutes long — no matter how good the toys are.